<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <h1>yahoo</h1>
    <script>
      class App {
        run() {
          document.querySelector('h1').addEventListener('click', () => {
            // console.dir(This)
            console.log(this)
          })
        }
      }

      let obj = new App()
      obj.run()
    </script>
  </body>
</html>
